Use RJ-45 port as a HPR AV-bay switch?

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soopirV

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Not sure if I had a light-bulb moment or a fever dream, so am pitching this out there- any reason I can't use an RJ-45 keystone jack as a switch/shunt? My thought is that there are two plugs- one is wired up with the deployment charge wires shorted, and the CPU power disconnected. This is the "remove before flight" plug. The other provides continuity to the cpu battery, and removes the short from the charges.
The keystone is recessed into the Avbay, and the plug isn't a hunk of cat5, just a few small jumpers crimped in securely. The mass is low, and it's a locking connection (and provides an 8p1t config). Should I go back to bed or draft up a schematic?
 

jpoehlman

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Not entirely a bad idea, but my concerns would be:

1: current capacity of the RJ 45 jack and plug, as they are design to carry signal not current.

2: the RJ 45 jack connection is effectively a wire formed to be spring loaded. With the high g forces of launch, ejection, etc this may not be reliable.

I've thought about using them internally for easy AV bay removal, but steered away due to the above mindsim results.

Jack
 

dhbarr

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PoE gear isn't typically rated above .5-.7A at 48v.
 

Steve Shannon

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Switches need to carry the full current required to light the electric match. That's usually less than an amp; all fire current is usually about 500 mA. These could work for that for a while but it would not be my first choice. I would look at a solid slug of copper in a fuse holder.
 

Dave A

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I use small heavy duty slide switches. PML used to sell them but you can find them with an online electronics company. (Newark, All Electronics, etc)

I mount them cross-ways, and space them off the inside where the tip of the switch just below the surface of the tube.
That way linear g-forces do not move the slide and an rigging flapping around don't shut it off either.
 

manixFan

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Interesting idea but I'm wary of anything that requires a small, easy to lose custom part that is not easily replaceable in the field. I learned that early on when I used a keyed switch to arm my electronics. Lose the key and no flight. I just recently started using magnetic switches which somewhat violates my rules but it's easy to have spare magnets and as they grow in popularity the odds I can borrow one are fairly high. Of course you could always just make up several spares to avoid problems. Other than the the magnetic switches all my other current rockets use screw switches.

Just something to think about,


Tony
 

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